2. The prices reported for this transaction range from $11.46 to $11.60; the reporting person hereby agrees to provide, upon request by the staff of the Securities and Exchange Commission, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

4. Mr. Green, John V. Balen, Deepak Kamra, Gregory Kopchinsky, Guy M. Russo, Eric A. Young (the "Canaan II Individuals"), Charmers Landing LLC ("Charmers"), Stonehenge LLC ("Stonehenge") and Waubeeka LLC ("Waubeeka") are managers of Canaan Equity Partners II LLC which is (a) the sole Manager of Canaan Equity II Entrepreneurs LLC and (b) the sole General Partner of each of Canaan Equity II L.P and Canaan Equity II L.P. (QP). The sole managers of Charmers, Stonehenge and Waubeeka are Mr. Green, Mr. Kopchinsky and Mr. Russo, respectively. Such individuals may be deemed to have shared voting, investment and dispositive power with respect to shares held of record by Canaan Equity II Entrepreneurs LLC, Canaan Equity II, L.P., and Canaan Equity II, L.P. (QP), but disclaim beneficial ownership of all shares except to the extent of any pecuniary interest therein.

5. Mr. Green, John V. Balen, Deepak Kamra, Gregory Kopchinsky, Seth A. Rudnick, Guy M. Russo, and Eric A. Young are Managers of Canaan Equity Partners III LLC which is (a) the sole Manager of Canaan Equity III Entrepreneurs LLC and (b) the sole General Partner of Canaan Equity III L.P. Such individuals may be deemed to have shared voting, investment and dispositive power with respect to shares held of record by Canaan Equity III, L.P. and Canaan Equity III Entrepreneurs LLC, but disclaim beneficial ownership of all shares except to the extent of any pecuniary interest therein.

6. Brenton K. Ahrens, John V. Balen, Maha S. Ibrahim, Deepak Kamra, Gregory Kopchinsky, Seth A. Rudnick, Guy M. Russo, Eric A. Young, Wende Hutton and Stephen Bloch are Managers of Canaan Partners VII LLC which is the sole General Partner of Canaan VII L.P. Such individuals may be deemed to have shared voting, investment and dispositive power with respect to shares held of record by Canaan VII L.P., but disclaim beneficial ownership of all shares except to the extent of any pecuniary interest therein. Mr. Green is not a member or manager of Canaan Partners VII LLC and does not have a pecuniary interest in the shares held by Canaan VII L.P.

7. Consists of 20,000 shares held by Canaan VII L.P.

8. The prices reported for this transaction range from $11.23 to $11.5104; the reporting person hereby agrees to provide, upon request by the staff of the Securities and Exchange Commission, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price.